Plastic aerosol container and method of manufacture

Abstract

Plastic aerosol container having a thermally crystallized neck finish configured to receive an aerosol valve assembly and an expanded strain oriented aerosol container body integral with the neck finish. A junction between the thermally crystallized neck finish and the strain oriented container body defines a pull point at which strain orientation begins.

Description

FIELD OF THE INVENTION[0001]The present invention relates to aerosol containers and more particularly to a plastic aerosol container able to withstand the elevated pressures and temperatures of testing and storage.BACKGROUND[0002]Aerosol containers are subject to problems such as creep, burst, and leakage. These problems may be encountered when the containers are subjected to high temperatures and pressures during packing, testing and / or storage. For reasons of public safety, the containers must be tested to ensure compliance with regulatory guidelines directed to structural integrity. According to one test, the aerosol container is filled at 130 psig (9.14 kgf / cm2 kilograms force / centimeters squared) and then heated to 131° F. (55° C.), causing the headspace pressure to rise to 140 psig (9.85 kgf / cm2), or higher; the sealed container must withstand these conditions without leaking or bursting over a time period selected to mimic the conditions of actual use and storage. The pressur...

AI Technical Summary

Benefits of technology

[0003]The problems of creep, burst, and leakage in plastic aerosol containers are solved in accordance with one embodiment of the invention by providing a container with two specific regions that together allow the container to withstand the severe testing and use requirements. More specifically, applicant has discovered that the neck finish and its transition to the enlarged container diameter is a source of the leakage and bursting problems with plastic aerosol containers. As a result, the prior art containers are deforming in these regions, leading to a loosening of the closure and / or valve assembly. Applicant solves this problem by providing a crystallized neck finish which not only thermally stabilizes the finish but also solves the problem of stretching the preform material properly below the neck finish during the blow molding process. More specifically, crystallizing the neck finish provides a means to control a point at which orientation begins during blow molding of the plastic aerosol container.

Problems solved by technology

More specifically, applicant has discovered that the neck finish and its transition to the enlarged container diameter is a source of the leakage and bursting problems with plastic aerosol containers.

As a result, the prior art containers are deforming in these regions, leading to a loosening of the closure and / or valve assembly.

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